QINGDAO -- Chinese civil aviation industry insiders have called for tighter regulation on illegal drone flights, as the country has become the world's largest manufacturer of consumer drones.

China currently has about 20,000 unregistered unmanned aerial vehicles (UAV), said attendees at the China UAV Safety Development Forum which opened in Qingdao, east China's Shandong Province, on Saturday.

Wu Qiang, deputy chief engineer of the China Aviation Industry Development Research Center, said illegal drone flights have threatened the safety of civil aviation flight operation.

For example, nine illegal drone flights near Chengdu Shuangliu International Airport in southwest China's Sichuan Province in April last year caused the cancellation of 43 flights and delayed 142 flights, while 112 others were diverted to alternate airports.

There should be increased supervision of safety of UAVs as more products come onto the market, Luo Ge, director of the China Association of Remote Sensing Application, said at the forum.

China Civil Aviation Administration (CAAC) has developed two cloud computing systems -- U-cloud and U-care -- for UAV flight registration and monitoring.

Every drone equipped with a chip of over 100 grams can access the U-care system and allow the system to track its flight movements and give timely warnings to the operator about flight zones and speed limits, according to Lan Yudong, developer of the U-care system.

Shi Rong, business director of the Huawei Wireless X Labs, said that in the future, aviation supervisors can rely on the 5G mobile network to verify a UAV and precisely locate its movements. The network can also assist UAV applications, he said.